Computer that could outlive the universe a step closer

A "TIME crystal" that can continue to work as a computer even after the heat death of the universe is a step closer to reality.

Crystals are three-dimensional objects whose atoms are arranged in regular, repeating patterns. They adopt this structure because it needs the lowest amount of energy possible to maintain.

Earlier this year, Frank Wilczek at the Massachusetts Institute of Technology introduced the idea of a time crystal. In such a crystal the atoms would rotate and return to their original location - repeating in time as well as space. Crucially, they would have to be in their lowest energy state as they do so, meaning that they would continue to rotate even after the universe has cooled to a uniform temperature - a state known as heat death (New Scientist, 18 January, p 6).

Wilczek proposed a time crystal design using a superconductive ring, but now Tongcang Li at the University of California, Berkeley, and colleagues have an alternative suggestion that may be easier to construct.

They propose using an ion trap, a device that holds charged particles in place via an electric field, to form a ring-shaped crystal. By applying a weak static magnetic field, the ions would rotate. Quantum mechanics dictates that the ions would continue to rotate even when the ring is cooled to its lowest energy state. The result is a time crystal (arxiv.org/abs/1206.4772).

"I'm very pleased with it," says Wilczek. "They've really come up with something that looks like a realisable experimental design."

If you would like to reuse any content from New Scientist, either in print or online, please contact the syndication department first for permission. New Scientist does not own rights to photos, but there are a variety of licensing options available for use of articles and graphics we own the copyright to.